Design of water distribution systems

Water distribution systems (WDSs) vary from simple to complex. The main objective of all water systems is to supply safe water for the cheapest cost. These systems are designed based on least-cost and enhanced reliability considerations, and design principles should satisfy both hydraulic and engineering requirements. The hydraulic requirements include pressure, velocity, sufficient flow, minimum operational cost, etc., and the engineering requirements involve selection of durable materials, system component configuration, ease of access to components, etc.

The chapter begins by considering the design objectives of WDSs. It describes performance indicators that can be used to drive WDS design. These include risk of low pressures and unplanned supply interruptions, and water quality standards, etc. The chapter then introduces optimisation techniques and how they can be applied in the planning and design of WDSs. A description will be provided on the role of multi-objective decision-making when optimising two or more conflicting objectives, and how this can be used to investigate the trade-offs involved between the conflicting objectives. The chapter concludes by providing a discussion on the need to develop WDSs that can cope with future uncertainties and change requirements.